Trenton police redeploy ShotSpotter system in larger area of city

Trenton police Detective Mike Davis describes how the new version of ShotSpotter works. (Kevin Shea | For Nj.com

TRENTON — ShotSpotter, the gunfire detection system Trenton police started using in 2009, has been expanded and re-loaded with better technology, the police department said.

As part of the final calibrations of the system, Trenton police officers fired handguns at three locations around the city Tuesday evening in controlled settings.

The city council voted last summer to expand the program, with a new $300,000 contract to breath new air into the program, which police leadership fought for.

The re-boot is now complete and the newer system went online May 1 with 3 square miles of the city being monitored for gunfire. The former system covered 1 square mile and was fraught with false detections.

Last year, a ShotSpotter employee said a Trenton had 1,500 shots-fired incidents in a one-year period, but only 556 of which were found to be incidents where a weapon was discharged.

The most significant change in the system, police Lt. Stephen Varn said, is a shift from city police dispatchers interpreting the popping sounds caught by ShotSpotter microphone sensors to professionals at the company analyzing reports of shots.

The former system, said Varn, the department's spokesman and ShotSpotter project manager, put a lot of onus on city police dispatchers, who had to listen to the sounds, determine if it was gunfire, then deploy officers.

Even if dispatchers felt the sounds were not gunfire, Varn said, they more than often sent a police unit, and many incidents were unfounded.

The ShotSpotter system on a Trenton police vehicle laptop. (Kevin Shea | For NJ.com)

Now, the 60 microphone detectors around the city will send the data to ShotSpotter's dispatch center in California where a trained official determines if is gunfire, or suspected gunfire.

If shots are confirmed, Varn explained, the company sends a report simultaneously to the Trenton dispatch center, and all patrol cars with ShotSpotter program on the vehicle's laptop.

That relay takes just 20 to 30 seconds and has already been vetted, Varn said. On an officers's laptop pops up a map with a red dot showing an exact location of the suspected shot or shots. Police can then listen to a recording of the gunfire.

Varn said the entire system is just better and faster. "We're going to get to jobs quicker instead of waiting for someone to call in and wait for dispatcher to dispatch it. We should be right on top of it."

To make sure the system recognizes accurate, real gunfire, Varn arranged for police officers to shoot guns at three city locations Tuesday evening.

Two officers took turns firing one and three-bullet bursts into the back of a dump truck loaded with sand while Varn kept in contact with dispatchers, in case residents reported hearing the shots.

Except for a few passersby who were steered away from the area, the tests were completed without incident and the tests were successful, Varn said.

Detective Mike Davis, one of the more experienced ShotSpotter users, said the system was already instrumental in an incident on Walnut Avenue recently in which responding officers made an arrest because they were able to respond very quickly.

"This is another tool in our arsenal that's going to be able to help us combat violent crime and hopefully maybe even save a life," Varn said. "Any advantage we can get is going to be a plus for the department."